Food Sensitivities And Autoimmune
Apr 09, 2023
Do you suspect that you are reacting to foods, but don't know which? The thought of doing an elimination diet is daunting and you're looking for customized list of yes/no foods to help fight inflammation?
Food sensitivity testing is used by numerous health professionals, including nutritionists (like myself) as a tool in developing a customized nutrition plan for clients.
YET, food sensitivity testing for autoimmune is not something everyone agrees on and some in the medical community question the validity of testing because a "food sensitivity" is not a fixed allergy, meaning it's not there for life, nor is it life threatening. However, those who use food sensitivity testing as part of their custom nutrition plan typically experience relief and quite quickly.
This makes it confusing.
In my 13 years clinical experience in working with women and their families on various health issues (including autoimmune), I have yet to have a client who has NOT had some sort of food sensitivity or intolerance that was making their physical symptoms worse.
I also have the personal experience of having grown up with fixed food allergies, food sensitivities and intolerances. I’ve been living with them for 54 years.
In this article, I explain:
- What is a food sensitivity vs allergy
- How do you test for food sensitivities
- Why I recommend food sensitivity testing
- How to navigate food sensitivity testing
What is a food sensitivity?
A food sensitivity is an immune response to food, specifically, immunglobulin G (an antibody - a "fighter that protects your body") in response to an antigen (an antagonist, a foreign invader the body doesn't recognize or perceives as a threat).
What does that mean?
"When your body feels it is under attack, it makes special proteins called immunoglobulins or antibodies. These antibodies are made by the plasma cells. They are let loose throughout the body to help kill antigens like bacteria, viruses, and other germs. The body makes 5 major types of immunoglobulins:
- Immunoglobulin A (IgA)
- Immunoglobulin D (IgD)
- Immunoglobulin E (IgE)
- Immunoglobulin G (IgG)
- Immunoglobulin M (IgM)
Immunoglobulin G (IgG) is the most common type... IgG is always there to help prevent infections. It’s also ready to multiply and attack when foreign substances get into the body." (John Hopkins Medicine on IgG deficiency and why it's important to have IgG antibodies in your system)
So, our bodies produce antibodies - immunoglobulins - as a protective mechanism against what it perceives as foreign invaders, and food sensitivity tests measure the IgG response to proteins in food. Food sensitivities are not fixed, meaning they can ebb and flow.
What is an allergy?
When someone has an allergy (food, animals, environment, chemical), there is an immediate and measurable immune response. The most common immunoglobulin measured is IgE. When there is an IgE response, typically, your response is fixed - it is there for life, or at least a long period of time.
An IgE reaction indicates a systemic immune response to the invader (like anaphylaxis, asthma, runny nose, itchy eyes, dermatitis). Other immunoglobulins are sometimes measured (like IgA - the mucous response), but IgE is the most common one measured when you visit an allergist.
To diagnose allergies, the most common test is the "scratch test" whereby the allergist pricks the skin, allowing a small amount of a protein to enter the bloodstream. The reaction is always to the protein in the substance, and immediate - usually 15 minutes.
Doctors diagnose allergies by this reaction - redness, swelling, itch. Doctors will sometimes use blood tests, when a skin test is deemed too dangerous (skin infection). Either way, these tests are important and can save lives. In the case of anaphylaxis (a life threatening allergy), allergists are a key part of the team.
Food allergies that mark an IgE response are typically fixed - meaning there's a good chance you have them for life.
What is a food sensitivity test?
A food sensitivity test marks your body's IgG response to 190 tested foods, plus the ability to add on candida antibodies to rule out if a person is reacting to yeast overgrowth (or the food).
The at-home kits are a dry blood spot test, meaning, you take a few drops of blood at home, and send your results back to the lab.
The lab then marks the IgG response to proteins in 190 common foods. They use a colour scheme for the tested foods along with a number score. The foods in red should be avoided, yellow in moderation and green, no worries. The marking scheme is based on the IgG response.
Food sensitivities vs allergies (my personal experience)
As a child, I was the kid at school covered in eczema that others did not want to touch. I was born into this world covered in eczema and it wasn't until I became a CNP, that I was able to get my skin under control. That is in part because of food sensitivity testing which led me to healing my gut and helping my immune system better self regulate.
I have seen allergists all my life and they have been helpful to improve my quality of life in various ways (environmental, animals and food). My environmental and animal allergies are still there BUT as I’ve learned to work on my health and detoxification pathways, my reactions are much less severe and I can even dog sit for friends!
My childhood food allergies (peas, peanuts, oats and oranges) have also lessened over the years. YET, I've developed new allergies into adulthood ... hazelnuts now require an epipen.
In my latest visit to the allergist, I actually had to push for this hazelnut testing as an itchy mouth (my symptom) didn't seem life threatening. I also asked about gluten and dairy because I was breaking out in eczema and ulcers in my mouth when I ate these foods.
Hazelnuts were a yes from the allergist ... definite allergy.
Gluten and dairy ... no, not an allergy. The advice I was given was to eat more ... there was no reason to cut them out of my diet, even though my skin said otherwise.
So, I ordered my first food sensitivity test to compare.
Some of the foods that were "fixed allergies" when I was young (ie., oats) showed up on the list, along with some new foods. According to the food sensitivity test, I was reacting to some of my previous allergies and now reacting to more nuts than simply hazelnuts. Wheat and dairy were also there.
My takeaway (at the time) was that there was a huge gap between the medical testing and natural testing, and somewhere in between was the path to me feeling better. I was right. After adjusting my eating plan to my food sensitivity testing, focusing on increasing nutrient dense foods and detoxification, and working to really fortify my gut health ...
My skin cleared up. My energy improved. My bowel movements were spectacular for the first time in my life (well formed, two a day). I was sooooo inspired I went back to school to study holistic and functional nutrition, and here we are today.
Do food sensitivity tests help with autoimmune? (my professional experience)
The short answer ... absolutely yes, but only when you review them with a critical lens and in context of the whole person.
In my professional, depending on your state of health, you can have heightened sensitivity to what is entering your body. State of mind, chronic inflammation, stress, physical injury, toxic overload, leaky gut and bacterial imbalances can all negatively influence your body's immune response and can contribute to food sensitivities.
When you are in a state of good health, your body is better able to process a wide variety of foods with little effort. This is no different than being able to fight off a cold/flu that is going around. However, when you are have chronic, lingering health issues, you might react to certain foods that wouldn't normally bother you because you're already in a pro-inflammatory state.
Food sensitivities are not the cause of autoimmunity. They are ONE part of the Inflammation Matrix that triggered your genetic response. That said, food sensitivity tests can help you quickly get a snapshot of what is going on inside your digestive tract and lower your inflammatory load.
With this in mind, I recommend food sensitivity tests under certain conditions:
- You are the type of person who has a hard time sticking with nutrition recommendations and do better with a list of YES/NO/CAUTION that are customized to you through a lab. This has more to do with compliance or motivation.
- You have already tried an elimination diet like Itis, Paleo, AIP or even gluten free, and feel you're still reacting to certain foods and aren't able to pinpoint what food is bothering you.
The reason why I recommend food sensitivity tests under these situations is to eliminate any possible external triggers - exterior irritants - that may cause an additional inflammatory response.
The goal is to let the body CALM DOWN and help reduce your inflammatory load (reactions) so your body can focus on healing and return to balance. This is a key part of the The Autoimmune Nutrition Triad ... and reducing your overall inflammatory load by feeding and fuelling better immune, digestive and hormonal responses.
This makes sense when you consider the role of IgG - to defend the body against against what it perceives as foreign invaders.
The usual protocol is to remove these foods for three to four months, during which time you increase the nutritional density (or value) of what you're eating to support better immune regulation (autoimmune response) as well as working on gut health (the reasons the body maybe perceiving what are healthy foods as triggering). This usually includes not only temporary dietary changes, but also specific supplements to help heal and seal the gut, as well as lifestyle changes, including stress reduction and detoxification.
Then you reintroduce one food at a time to see if your body still reacts.
Reactions can take up to four days, so it's important you REALLY pay attention to how you feel - physically and emotionally. It can vary from person to person. Here is a short list of possible reactions
- Skin: itchy, dry skin, eczema flare, hives
- Brain: headaches or migraines, brain fog, irritability, mood swings, difficulty concentrating, hyperactivity
- Digestion: constipation, diarrhea, stomach pains, gas/burping
- Other: aches/pains, sinuses, disrupted sleep, urinary incontinence
If you are still reacting, we remove the trigger food for another few months, and so on. The goal is to get you back on track, eating all the foods you want to enjoy. However, unless the underlying reason as to WHY there is inflammation is not resolved, the food sensitivities may linger. The process is individualized and a journey.
And this is where critics of IgG testing really miss the mark.
They look only at the test and not the application or individual's larger health history or symptoms. Nor do they address the many root issues as to WHY a person would be reacting to foods and HOW to go about bringing things into balance.
Common mistakes people make with a food sensitivity test
There are a couple of red flags that jump out at me with these tests. I don't want you to waste your time, money or energy on similar mis-steps, so please let me help you avoid these things:
Trying to save money by ordering the cheapest test: tests vary in the number of foods they test. I believe in looking at more (vs less) to give you the most accurate picture of what's going on with you. It's worth the extra money to understand where the digestive breakdowns and food patterns are.
Thinking that all you need to do is avoid the list and you'll "heal your gut": Nope. The test is a tool that requires understanding as to WHY you're having the reactions (breakdown in the digestive cascade). Unless the why is identified, you'll waste your time and money with the test when you go straight back to eating what you were previously eating with no other internal or influencing changes.
Thinking you can simply switch from one food to another: For example, say your test results shows you're reacting to most of the nuts on the list, but not pecans. So, you double down on eating pecans for the next four months to get your nut fix. The question you should be asking is ... why am I reacting to so many nuts and what can I do about it?
Thinking this is a forever way to eat: This leads to malnutrition and is a miserable existence. One of our members with MCTD (rheumatic disease + IBS) came to us in 2025 avoiding the list of foods that she was given by another practitioner in 2018. Thankfully, we have helped her support her gut health, rebalance her microbiome and she is eating more variety (and feeling better) in six months versus the past 7 years.
Navigating food sensitivities when you have an autoimmune or inflammatory condition
Living and working around food allergies or sensitivities doesn't have to be limiting. Many of my clients panic when we look at food sensitivity test results that look like a Christmas tree of red, yellow and green responses, but once they realize, "hey, there are lots of great things I can eat," and I give them tools to cope using my Reality Based Meal Planning Method ... they start to FEEL BETTER while enjoying what they're eating.
The good news is that there are so many options and substitutions you can draw on. I encourage you not to dismiss food sensitivity testing if you have a chronic health issue based on one bad review or naysayer. The results can be helpful and liberating in your overall health plan.
If you're interested in learning more about whether food sensitivities are a good option for you, I encourage you to book a free call with me. This test and these calls can be helpful if you have:
- A skin disease, like eczema, psoriasis or rosacea (stems from the gut)
- Inflammatory bowel disease or irritable bowel syndrome
- High inflammation, pain or fatigue
- An autoimmune disease, and you have already completed an elimination diet, like the ones I offer inside of our monthly membership
The process I use, is quite simple, straightforward and effective in helping you step back in control of your body and health:
- Complete a health assessment and order your food sensitivity test. I include gut markers like Candida in this process as the majority of my clients have a history of birth control, HRT, prednisone or antibiotics. Sometimes clients will bring tests they have done on their own to me and we can work off of these versus recreating the wheel.
- Create a custom plan that removes the trigger foods and includes increasing nutrition dense foods. This includes simple meal planning for you, and any other family members you're responsible for feeding.
- Create a custom supplement and lifestyle plan to address microbiome imbalances fuelling food reactions. We benchmark symptoms during this process to ensure symptoms are improving (skin, energy, pain, digestion, metabolic markers for health).
- Reintroduce foods for more flexibility (usually 3 - 4 months later).
- Move onto maintenance, with a focus on living in a way that aligns with your health goals.
If this sounds like the kind of support you're missing, I encourage you to connect so we can discover where you need most help and what will bring you the best possible results.
